Dalbergia Assamica Benth - A Detailed Description
Dalbergia assamica Benth. is commonly known as Assam padauk, which belongs to the family Fabaceae. It is a deciduous tree that grows up to 30 m tall and has a broad crown that spreads up to 10-12 m. The bark is greyish-brown and exfoliates in irregular patches. The leaves are alternate, imparipinnate, and 15-30 cm long, bearing 5-9 pairs of leaflets that are 6-13 cm long and 2-5 cm wide.
The flowers of Dalbergia assamica Benth. are small and white, arranged in axillary racemes that are 4-8 cm long. The fruit is a flat pod, 6-10 cm long and 2-2.5 cm wide, containing 1-4 flat and rounded seeds that are enclosed in a hard seed coat.
Origin and Distribution
Dalbergia assamica Benth. is native to the northeast region of India, specifically the states of Assam, Manipur, and Nagaland. It also grows in Myanmar, Thailand, and Cambodia. The tree prefers hilly terrain and is found in forests at elevations of 600-1,500 m above sea level.
Common Names and Uses
The tree is known by various local names, including Assam padauk, Burmese padauk, and Thai padauk. Dalbergia assamica Benth. is highly valued for its timber, which has a beautiful reddish-brown color and is used in furniture making, decorative veneers, turning, and carving. The wood is also favored in musical instrument making, particularly for guitar backs and sides. It is known for its resonance, clarity, and excellent tonal qualities.
Aside from its wood, Dalbergia assamica Benth. has medicinal properties. The bark and leaves of the tree are used in traditional medicine to treat fever, digestive disorders, and skin diseases. The seeds of the tree are also used to produce oil, which is used in soap and cosmetic manufacturing.
The tree is also used in agroforestry systems and is planted for soil conservation, erosion control, and as a shade tree in coffee plantations. It is an important ecological resource for wildlife as it provides food and habitat for animals such as birds and mammals.
Growth Conditions for Dalbergia Assamica Benth.
Dalbergia assamica Benth. is a deciduous tree species that grows up to 20 meters in height. It is native to South Asia, specifically the Assam region in India. The plant is valued for its wood, which is used in furniture-making, musical instruments, and decorative items. To ensure proper growth and development of this species, certain specific growth conditions must be met.
Light Requirements
For healthy growth, Dalbergia assamica Benth. requires plenty of sunlight. The plant should be grown in areas with full sun exposure, as it is a light-loving plant. It requires a minimum of 6 hours of direct sunlight each day to thrive. Lack of adequate sunlight makes the plant susceptible to pests and diseases, while excessive sunlight can lead to scorching of the foliage.
Soil Requirements
Soil is a critical factor in the growth of Dalbergia assamica Benth. The plant thrives in well-drained, loamy soils with a pH range of 6-7. The soil should be rich in nutrients, and it should be properly amended with organic matter before planting. The ideal soil for this species must be able to retain water without getting waterlogged, as waterlogging can lead to root rot.
Temperature Requirements
Dalbergia assamica Benth. grows well in tropical and subtropical regions, with temperatures ranging from 18 to 33°C. The plant is sensitive to frost, and it cannot tolerate temperatures below 10°C. Therefore, it should be grown in areas with a warm and humid climate.
Water Requirements
Adequate water supply is crucial for the growth and development of Dalbergia assamica Benth. The plant requires regular watering, especially during the dry season. However, excessive watering should be avoided as it can lead to waterlogging, which can result in root rot.
Nutrient Requirements
For optimal growth of Dalbergia assamica Benth., the plant requires macronutrients such as nitrogen, phosphorus, and potassium. These nutrients are necessary for the plant's growth and development. Additionally, the plant requires micronutrients such as calcium and magnesium. It is important to ensure that the soil is adequately amended with these nutrients to boost the plant's growth.
Cultivation Methods
Dalbergia assamica Benth. is a tree species that grows well in warm, humid, and tropical climates, including India, Indonesia, and the Philippines. It requires well-drained and nutrient-rich soil with a pH level of 5.5-6.5 for optimal growth. The species can be propagated from seeds or cuttings.
If propagation is done by seeds, it is recommended that the seeds should be soaked in warm water for 24 hours before planting. After planting, it is crucial to ensure that the soil remains moist until the seedlings emerge. During transplanting, the plant should be spaced at intervals of 6 meters apart for proper growth.
Watering Needs
It is essential to keep the soil moist by watering the plant regularly, especially during the dry season. Young plants require more water than mature ones. Inadequate watering can lead to wilting, leaf drop, and stunted growth. However, excessive watering can also lead to root rot and other fungal diseases.
Fertilization
Proper fertilization helps to promote the growth and development of the plant, as well as enhance its resistance to pests and diseases. A balanced fertilizer of nitrogen, phosphorus, and potassium should be applied in the ratio of 4:2:1. Fertilization should be done during the rainy season, and the application should increase gradually as the plant grows.
Pruning
Pruning is a crucial task in the care and maintenance of Dalbergia assamica Benth. It helps to control the size and shape of the plant, promote better air circulation, and prevent the plant from becoming overgrown. Pruning should be done during the dry season, and the cuttings should be treated with fungicide to prevent infections. Over-pruning can lead to stunted growth, damage to the bark, and death of the plant.
Propagation Methods for Dalbergia assamica Benth.
Propagation of Dalbergia assamica Benth. can be carried out by both sexual and asexual methods. Some of the common propagation methods are as follows:
Seed propagation
The seeds of Dalbergia assamica Benth. are collected during the ripening period and sown directly in the field. The seeds require pretreatment before sowing as they have a hard seed coat. The pretreatment methods include scarification, soaking in hot water or sulfuric acid, and stratification. Germination of seeds occurs within 4-6 weeks after sowing.
Cuttings propagation
Cuttings of Dalbergia assamica Benth. can be taken from mature trees during the dormant season. The cuttings should have a length of about 10-15 cm and a diameter of 0.5-1 cm. The cuttings should be treated with a rooting hormone and then planted in the rooting medium. The rooting medium should be kept moist and covered with a transparent plastic sheet to maintain high humidity. Roots develop within a few months.
Grafting propagation
Grafting of Dalbergia assamica Benth. is commonly done using the cleft grafting method. Rootstock should be selected from healthy and vigorous trees, and scions should be taken from the desired cultivar. The graft union should be wrapped with grafting tape to maintain moisture and prevent disease infections. Grafting should be done during the dormant season, and the plant should be kept in a humid environment until active growth is observed.
Disease and Pest Management for Dalbergia Assamica Benth. Plants
Dalbergia assamica Benth. is a valuable timber tree species that is vulnerable to diseases and pests. Disease and pest management is crucial to ensure healthy growth and maximum yield.
Common diseases affecting Dalbergia assamica Benth.
Several diseases can affect this plant, including:
- Leaf spot
- Rust
- Stem canker
- Root rot
Leaf spot
Leaf spot is a common problem in Dalbergia assamica Benth. plants. It is caused by fungal pathogens and results in the formation of small, circular spots on the leaves. These spots can coalesce over time, leading to the death of the leaves. To manage this disease, it is important to remove infected leaves and prune the plant properly. Additionally, fungicides can be applied to prevent the spread of the pathogen.
Rust
Rust is another fungal disease that affects Dalbergia assamica Benth. plants, characterized by rusty, orange spots on the leaves. It can cause defoliation and stunted growth if left untreated. To manage rust, it is important to remove infected leaves and spray the plant with fungicides.
Stem canker
Stem canker is a fungal disease that causes cankers or lesions on the stem of the plant. The cankers can rapidly enlarge and girdle the stem, leading to plant death. To manage stem canker, it is important to prune diseased parts of the plant and apply fungicides.
Root rot
Root rot is a fungal disease that affects the roots of the plant, causing them to become black and mushy. It can lead to wilting, stunted growth, and death of the plant. To manage root rot, it is important to provide proper drainage by avoiding waterlogging and applying fungicides.
Common pests affecting Dalbergia assamica Benth.
Several pests can affect this plant, including:
- Bark-eating caterpillars
- Shoot borers
- Aphids
Bark-eating caterpillars
Bark-eating caterpillars can cause extensive damage to the stem of the plant by feeding on the bark, leading to girdling and death of the plant. To manage bark-eating caterpillars, it is important to prune and burn infested branches and apply insecticides.
Shoot borers
Shoot borers can cause damage to the young shoots of the plant by tunnelling into them. This can cause wilting of the shoots and stunted growth of the plant. To manage shoot borers, it is important to prune and destroy infested shoots and apply insecticides.
Aphids
Aphids are small insects that feed on the sap of the plant, causing wilting and stunted growth. To manage aphids, it is important to remove infested leaves and apply insecticides.
In conclusion, disease and pest management is crucial for ensuring healthy growth and maximum yield of Dalbergia assamica Benth. plants. A combination of cultural, mechanical, and chemical control measures can be used to manage the diseases and pests effectively.
